Getting your plane off the ground
There is an old saying among pilots: Takeoffs are voluntary, landings are mandatory. You don't have to take off unless conditions are safe and appropriate for your model and skill level but, once you are in the air, you have to land whatever the weather and in the face of any problems your model might be experiencing. In other words, it is essential to make sure that everything you can check is checked before you take off.
The instructor stands near the student and keeps a careful eye on the model. (Ralph Voorhees teaches Aenea Raskin,
both of the San Francisco Vultures).
Professional pilots use a printed checklist, so you shouldn't be embarrassed to do the same. We've already seen some of the airplane checklist earlier in the series, but now we add some things that the instructor had previously taken care of and which are now or soon will be your responsibility.
Site:
• Is there room to land with a suitable approach?
• Is the surface such that landing will not damage the plane?
• Is there a frequency control board?
If so, learn how to use it. If not, make sure your frequency is clear by
checking what channels others are using, and strongly announcing yours before you turn it on.
• Are there people or animals that you might hit or that might cause damage to the plane (or you!)?
• Are there things you might accidentally damage with the plane or when you walk to retrieve it?
• Is it legal to fly a model plane at this location?
• Do you need permission to fly there?
Wind:
• Is the wind too strong? If you are slope soaring, you may also have to ask if it is too weak?
• Is the wind coming from a useful direction such that you can take off and land into the wind?
• Is the wind gusty?
• Has the wind just gone over trees or buildings that might make it turbulent?
Plane:
• The plane must balance where the instructions say it should.
• Make sure that the surfaces are at proper angles to each other, that the plane is right/left symmetrical, and that wings and tail parts are not warped.
• Visually inspect the plane. For
example, check that all servo output arms are secured with screws, and any clevises are properly closed.
• With everything turned off, make sure that there’s nothing loose by
tilting the plane in all directions.
• Check that the control surfaces have little or (best) no play in them.
• Make sure your frequency is clear - that nobody else is using it.
• If the frequency is clear, turn on the transmitter, and check the meter or lights to see that it is fully charged.
• Turn on the receiver. If you have not done so recently, do a range check as per the instructions that came with the transmitter.
• Check that all
control surfaces move smoothly and in the proper directions
• Make sure that the motor and gearbox operate smoothly and without excessive vibration.
Before The Takeoff
Oddly, the first thing you must think about in planning a flight is the end of the flight-the landing. I remember when I was new to RC and had just learned to take off and land at the club field and was overconfident in my new skills. I took my plane to an unfamiliar place to show off my piloting to some friends. It was a small, empty parking lot, about the size of the runway I was accustomed to. I took off and found that the trees, which surrounded the lot on all sides, forced me to turn a lot more frequently than I was used to. When it came time to land, there was no room to set up a proper approach. I had to fly a curved path, which makes the landing point nearly impossible to judge (it’s hard enough to get a straight-in landing to touch down where you want it to) and the plane ended up smashed against a curb. Could I now land there safely? Maybe, but now I know better: I would not even try to fly that airplane at that location.
What I had yet to learn is that to make good, consistent landings, you need not only an adequate landing area, but room to get the plane lined up, as well as more room than you think to allow for errors and to get the plane on the ground and safely stopped. Sure, you can sometimes luck out with a catch-as-catch-can approach, straightening out at the last second, but it fails more often than it succeeds. It's hard enough to make a smooth landing under good conditions. Good judgement counts as much as flying skills in keeping your plane operating safely (and in one piece).
Taking Off
Hand Launch or Take Off From Ground? (This discussion relates to powered models. Glider launching will be covered in a later installment)
Some planes do not have landing gear (or should we call it "take off gear"?), and must be hand-launched as we described earlier in this series. If there is a suitable surface and your aircraft is equipped to take off from the ground (in modeler's jargon, we use a three-letter code and say that it can "R-O-G" for "rise off ground") the question is: should you take off this way?
What is a suitable surface? It depends on your model. For a seaplane (which I do not recommend to beginners) it is a calm body of water. For models with small diameter wheels, say, under two inches, you need a smooth surface. Asphalt, concrete, or even a smooth patch of hard-packed earth will do. Larger models can take off from rougher surfaces. My 9-foot-span electric-powered camera plane has 4" diameter wheels and can take off and land safely on pretty rough grass fields, even if full of gopher holes.
If your plane has landing gear, and you have a suitable surface, and there is enough airspace for a long, straight-in approach, you have a choice. I personally prefer ROG to hand-toss. If the plane can’t fly, it will never get off the ground, but in a hand-toss that same plane may become an instant wreck. For a beginner, whose reaction to aircraft motion is not yet automatic, it is hard enough to fly the airplane, much less launch it - especially that critical first time when the plane may be far out of trim and want to dive, stall, or roll into the ground.
At our field we have the luxury of a hill along one side, and sometimes we hand-launch from 20 feet up, which gives an experienced pilot time to sort out problems and, if the plane if flyable, to get it flying right whereas if it had been hand launched from the flats, it would have already crashed. There is safety in altitude. As always, if you can get an expert flyer to test and trim your model, you are miles ahead in learning to fly.
Tail Dragger or Trike Gear?
Some planes, especially those with "conventional" gear (two main wheels up front and a small skid or tail wheel in back - also called "tail draggers") will just not take off the ground. They will spin around, dig in a wingtip, skitter up and down, or dance in any direction except straight ahead into the wind. There are a number of causes, the most common are: landing gear too far forward, landing gear legs too springy or (rarely) too stiff, not enough power, one or more wheels not rotating freely, or one or more wheels are not pointed parallel to the centerline of the airplane (actually, it's better if both wheels have a tiny bit of toe-in, but that's a refinement). Some tail draggers (the Wingo is a good example) always take off easily, and some require quick but smooth rudder operation to take off; flying such models off the ground is a separate and hard-earned skill. Beginners should have an expert make sure that their airplanes are among those that take off effortlessly.
Tricycle landing gear, where there is one wheel at the nose of the aircraft and two wheels farther back, is lots easier to both take off and land with. There is a reason that all airliners have tricycle landing gear. Unfortunately, few beginner planes have this feature. Almost all of the problems noted for conventional gear just don't happen with tricycle gear. The disadvantages of "trike" gear is that it's heavier, more expensive, has more air resistance, and is not nearly as good (for a given wheel size) on rough fields. Also, in bad landings, the front unit takes quite a beating and is a weak point in many designs.
The Takeoff
Finally, we have the airplane accelerating down the runway, at full throttle, into the wind. Now what? The most important thing is to stay calm, and not overcontrol. The plane will probably take off all by itself. At most you should need only a little rudder to keep it pointed straight and a tad, not more, of up elevator (lean back just a little, do not pull, on the stick) to get off the ground. The most common mistake in taking off is to point the nose of the plane up too high, which almost inevitably causes a crash.
Another common mistake is to start to turn too soon. After the plane leaves the ground, it is still picking up speed. Turning slows the plane just when it needs more speed, and you tend to lose altitude - which you don't have much of yet - in a turn.
So let the plane fly straight ahead while it climbs to a safe altitude (say, at least 3 meters (10 feet)) before you apply any controls.
Once at altitude, your plane may need to be trimmed so that it flies straight and level when the stick is released, but that discussion is for another time.
And never forget to run through your check list before each takeoff!
